South Carolina - Wood Frame Structures

Key Concepts

OSHA responsibilities and definitions - A competent person is "one who is capable of identifying existing and predictable hazards in the surroundings or working conditions which are unsanitary, hazardous, or dangerous to employees, and who has authorization to take prompt corrective measures to eliminate them" (29 CFR 1926.32(f)). No degree, years of experience or certificate is part of this definition. - A qualified person is defined separately by recognized degree, certificate, professional standing, or extensive knowledge, training and experience (1926.32(m)). - Employer accident-prevention programs must provide "frequent and regular inspections of the job sites, materials, and equipment ... by competent persons designated by the employers" (1926.20(b)(2)). Only employees qualified by training or experience may operate equipment (1926.20(b)(4)). - OSHA issues and enforces standards, conducts workplace inspections and assesses fines; employers must keep the workplace free from recognized hazards, provide training for hazardous work and PPE, and comply with record-keeping and accident-reporting standards (Carpentry and Building Construction, Ch. 3, pp. 78–79).

Key Concepts

SC 811 notice and locate requests - Notice for excavation not involving a subaqueous facility must be given within three to twelve full working days before the proposed commencement date; notice near a subaqueous facility must be given within ten to twenty full working days (Section 58-36-60(A); SC 811 Excavator Manual p. 13). - A notice expires within fifteen working days after the date of notice; no excavation may continue past that period without a subsequent notice (Section 58-36-60(B); Manual pp. 15, 55). An Update should be submitted at least 3 full working days before the original notice expires (Manual p. 15). - Each locate notice is not to exceed ¼ mile (1320 feet) in length or five adjoining addresses (Manual p. 16; 58-36-60(C)(5)). - Before digging, the excavator must check positive response, must premark with white paint, flags, or stakes when the site cannot be clearly identified, and, if an unmarked facility is observed, must make an additional call and arrange marking within three hours (58-36-60(E)(1), (2), (6)). - Tolerance Zone = one-half the known diameter plus twenty-four inches on either side of the designated center line (58-36-20(21)(a); Manual pp. 28, 46). For a subaqueous notice the Tolerance Zone is 15 feet on either side (Manual p. 13). - Emergency excavation is exempt from the notice requirements (the 3-full-working-day wait) in Section 58-36-60, but oral notice to the notification…

South Carolina Wood Frame Structures | 9 questions (18% of exam)

Key Concepts

Materials and hydration - Concrete = cement + coarse aggregate + fine aggregate + water. The chemical reaction when water combines with cement is hydration. If coarse aggregate is missing, the material is mortar or grout. (Carpentry and Building Construction, Ch. 8) - Portland cement types: Type I standard; Type II modified (sulfate resistance, lower heat); Type III high-strength, gains strength faster — used where forms must be removed quickly or concrete must be put in service quickly; Type IV low heat; Type V sulfate-resistant for highly alkaline conditions. (Page 219, Table 8-1)

Ordering and mixing - Five-bag mix (five bags of cement per cubic yard) is the minimum considered acceptable for most work. Six-bag mix is commonly specified where high strength is needed or steel reinforcement is used. (Page 226) - A 60-lb. sack of pre-mix yields 1 cubic foot. If a job requires more than 12 sacks, it is generally more efficient and less expensive to obtain concrete by other means. (Page 224) - Slump: paving and floor slabs — 1" minimum to 4" maximum; columns and walls — 4" to 8". (Page 227)

Key Concepts

Floor framing components - Floor framing consists of posts, girders, sill plates, joists or trusses, and subflooring (Carpentry and Building Construction, Section 15.1, p. 396). - A wood post supporting a girder must be solid and not less than a 4×4 nominal size; a 6×6 is often used depending on the load (Section 15.1, p. 396). - Ends of wood girders should bear at least 4" on masonry walls to reduce the risk of crushing the wood fibers (p. 401). - A ½" clearance is provided at each end and each side of a wood girder framed into masonry, to prevent the wood from absorbing moisture (Chapter 15, Built-Up Girder discussion, pp. 399–401). - Sill plates: at least two ½" bolts per plate, spaced no more than 6' OC, with a bolt within 12" of each end of every plate section (p. 268). - Joist layout begins with a mark 15¼" from the outside edge of the sill plate so "a joist is centered every 4'" and sheathing panel edges fall on a joist centerline (Section 15.2, p. 405). - Joists are doubled under a bearing wall parallel to them; where pipes or ducts must pass, doubled joists may be separated by blocking cut from the same size stock, spaced not more than 4' (48") OC (p. 411).

Key Concepts

Truss installation sequence & temporary restraint (BCSI-B2) - BCSI-B2 applies to trusses spaced up to 2 feet on center and up to 80 feet in length; BCSI-B1 covers trusses spaced up to 4 feet on center and up to 80 feet in length. - Step 1: establish the ground bracing procedure, exterior or interior. Interior ground bracing is used where ground level is too far from the truss (steeply sloping terrain or upper-level installations), because exterior ground brace diagonals get exceedingly long (BCSI-B2, Figure B2-2). - Step 2: determine the on-center spacing of Top Chord Temporary Lateral Restraint (TCTLR) per Table B2-1. Step 3: set the first truss (or gable end frame) and fasten it securely to the ground bracing verticals using minimum 2-16d (0.135x3.5") nails at each junction and to the wall, straight, plane and plumb. - Step 7: install bottom chord temporary lateral restraint and diagonal bracing. Do not remove ground bracing until all top chord, web and bottom chord lateral restraint and diagonal bracing is installed for at least the first five trusses (BCSI-B2, Steps 1–8). - Step 8 Option B: after the initial group of five trusses is installed and braced, do not set more than four trusses using Short Member Temporary Lateral Restraint before stopping and installing diagonal bracing (BCSI Guide, Page 28). - Minimum size of lumber used as Lateral Restraint and Diagonal Bracing…

Key Concepts

Framing terminology (Carpentry & Building Construction, Section 17.1, pp. 468–470) - A rafter is an inclined member of the roof framework; a ridge board connects the upper ends of the rafters. A collar tie is a horizontal tie connecting opposite pairs of rafters to help stiffen the roof (Section 17.1, p. 468). - Span = distance between the outer edges of the top plates; total run = one-half the span. Unit run of a common rafter is always 12"; for a rafter at 45° to the ridge (hip/valley) it is 17" (p. 470; p. 505). - Slope is a ratio of rise to run; pitch is a ratio of rise to span. They are not synonyms (p. 470).

Rafters and ridge - Hip and valley rafters are the same thickness as common rafters but should be 2" wider in nominal dimension — 2×6 commons take 2×8 hips — to give full bearing to intersecting jack rafters (Ch. 18, p. 504). - Hip rafter shortening allowance: framed against the ridge board with a single side cut = one-half the 45° thickness of the ridge board; framed against the common rafters with a double side cut = one-half the 45° thickness of a common rafter (Ch. 18, p. 509). - A nonstructural ridge board is usually nominal 2" lumber slightly wider than the rafter stock: 2×8 rafters → 2×10 ridge (p. 530).…